After Catherine II ascended the throne, Peter III's favorite regiment, consisting of German Holsteiners, was disbanded, but several officers remained in St. Petersburg. A conspiracy arose - the Holsteins were going to kill the empress. The place for preparing the assassination attempt was chosen with calculation - near the estate of Count Orlov-Chesmensky, who, by all accounts, was offended by the empress for his resignation. If something goes wrong, he will be the culprit... Having learned that something is up, Moscow Chief of Police Arkharov sends his proven agents to conduct a search...